Various electric vehicles or hybrid vehicles are developed recently as plug-in vehicles so that a storage battery of such vehicles may be charged by a commercial power source available at home for example.
The plug-in vehicle is parked in a parking garage of a home after certain travel and its battery is charged to prepare for a next travel event. According to a power line communication system of an electric vehicle, as disclosed in JP 2003-23378A, the electric vehicle is charged by using a home power supply network. Security of the vehicle needs to be assured while it is being charged. Therefore, it is proposed in JP 2003-23378A to allow the charging only when identification codes (ID) assigned to the electric vehicle and to the power outlet of the power supply network correspond to each other or to issue an alarm by a visual display device if the vehicle is disengaged from the power outlet without releasing a security key.
It is desired, however, that the plug-in vehicle management system provide much higher security or additional application functions.